nuttx/libs/libc
chao.an c8784faf3c ctype/iscntrl: correct the control character function
all the characters placed before the space on the ASCII table
and the 0x7F character (DEL) are control characters.

Signed-off-by: chao.an <anchao@xiaomi.com>
2021-01-05 01:34:36 -06:00
..
aio syscall: Fix typo error in cvs and header file 2020-05-07 10:31:05 -06:00
assert arch: up_assert shouldn't call exit directly 2020-07-19 01:21:36 +01:00
audio Replace all wget with curl 2020-12-22 03:36:10 -06:00
bin style/Makefile: remove unnecessary trailing whitespace 2020-11-28 12:20:30 +01:00
builtin builtin: Remove HAVE_BUILTIN_CONTEXT macro 2020-05-01 10:43:47 -03:00
ctype ctype/iscntrl: correct the control character function 2021-01-05 01:34:36 -06:00
dirent libc/ftw: Fix error: cast between incompatible function types from 'ftw_cb_t' nftw_cb_t 2020-08-11 08:16:58 -07:00
dlfcn libc: Replace all malloc/free to lib_malloc/lib_free 2020-07-29 10:14:27 +01:00
endian Remove the unused libs/libc/endian/Kconfig 2019-01-27 06:58:01 -06:00
errno Completes the Implementation of the TLS-based errno 2020-05-07 23:11:34 +01:00
eventfd fs/vfs: Add file descriptor based events support 2020-07-31 15:09:35 -06:00
fixedmath
grp libc: Replace all malloc/free to lib_malloc/lib_free 2020-07-29 10:14:27 +01:00
hex2bin libc: Replace all malloc/free to lib_malloc/lib_free 2020-07-29 10:14:27 +01:00
inttypes
kbin build: Remve the unnecessary .gitignore 2020-05-23 18:00:40 +01:00
libgen
locale libc/locale: Add the mininal support for locale_t operation 2020-06-15 07:20:19 -06:00
lzf Refine the preprocessor conditional guard style (#190) 2020-01-31 19:07:39 +01:00
machine libs/libc/machine/risc-v/rv64/arch_elf.c: Don't assume binfo expansion 2020-12-06 09:03:09 -06:00
math math: Make this friendly with libcxx 2020-10-25 07:30:14 -07:00
misc libc/dumpvbuffer: update the vector ptr correctly 2020-12-29 15:42:33 -08:00
modlib libs/libc/modlib/modlib_symbols.c: Fix syslog formats 2020-11-21 19:38:32 -08:00
net libs/libc/net: implement socketpair 2021-01-03 20:56:27 -06:00
netdb libc/netdb: Move hostbuffer out of the stack 2020-12-22 10:40:22 -03:00
pthread pthread_mutexattr_getprotocol: modify prototype 2020-12-02 07:52:15 +01:00
pwd libc: Replace all malloc/free to lib_malloc/lib_free 2020-07-29 10:14:27 +01:00
queue libs/libc: fix typos in comments 2020-12-13 09:06:28 -06:00
sched sched: Call c++ global variables constructor inside nxtask_startup 2020-07-01 07:55:33 -06:00
semaphore libs/libc/semaphore/sem_getvalue: correct get_value descriptions 2020-07-04 00:36:02 -05:00
signal libs/libc/signal/sig_pause.c: Fix a comment 2020-10-28 07:12:46 +01:00
spawn libs/libc/spawn/lib_psa_dump.c: Fix a syslog format 2020-12-05 08:13:32 -06:00
stdio libs/libc: fix typos in comments 2020-12-13 09:06:28 -06:00
stdlib libc/stdlib: Fix range check in strtoul(l) 2020-11-12 06:01:33 -08:00
string libs/libc/string/lib_strcspn.c: fix function name in comment 2020-12-08 12:58:40 -06:00
symtab Change all files come from Xiaomi/Pinecone to Apache License 2.0 2020-08-22 17:37:21 -06:00
syslog setlogmask(): Add comments 2020-05-11 11:32:55 -04:00
termios serial/termios: support custom baud rate setting 2020-10-21 10:11:21 -07:00
time libs/libc/time/lib_strftime.c: Fix a printf format warning 2020-11-16 08:29:00 -08:00
tls include/nuttx/sched.h: Make naming of all internal names consistent: 2020-05-09 14:19:08 -03:00
uio libc/uio: enable writev() for sockets 2020-09-21 19:31:06 -07:00
unistd libc: Implement posix_fallocate 2020-12-14 09:20:15 +01:00
userfs libc: Replace all malloc/free to lib_malloc/lib_free 2020-07-29 10:14:27 +01:00
uuid crypto/arc4random: rename getrandom to arc4random_buf 2020-12-13 08:49:51 -06:00
wchar libc: Fix warning: implicit declaration of function ‘strnlen’ 2020-06-03 07:46:02 -06:00
wctype
wqueue libc: Replace all [nx]sem_xxx with _SEM_XXX 2020-08-18 07:59:21 -07:00
zoneinfo Replace all wget with curl 2020-12-22 03:36:10 -06:00
.gitignore build: Remve the unnecessary .gitignore 2020-05-23 18:00:40 +01:00
Kconfig audio: libsamplerate: add initial audio Sample Rate Converter 2020-11-19 18:05:47 -08:00
libc.csv libc: Add opterr global variable 2020-11-21 07:01:08 -06:00
libc.h libc/stdio: Allocate file_struct dynamically 2020-09-11 17:58:17 +08:00
Makefile build system: add missing --obj-path to MKDEP 2020-11-28 09:59:56 -06:00
math.csv syscall: Fix typo error in cvs and header file 2020-05-07 10:31:05 -06:00
README.txt Completes the Implementation of the TLS-based errno 2020-05-07 23:11:34 +01:00

lib
===

This directory contains numerous, small functions typically associated with
what you would expect to find in a standard C library.  The sub-directories
in this directory contain standard interface that can be executed by user-
mode programs.

Normally, NuttX is built with no protection and all threads running in kerne-
mode.  In that model, there is no real architectural distinction between
what is a kernel-mode program and what is a user-mode program; the system is
more like on multi-threaded program that all runs in kernel-mode.

But if the CONFIG_BUILD_PROTECTED option is selected, NuttX will be built
into distinct user-mode and kernel-mode sections.  In that case, most of the
code in the nuttx/ directory will run in kernel-mode with exceptions
of (1) the user-mode "proxies" found in syscall/proxies, and (2) the
standard C library functions found in this directory.  In this build model,
it is critical to separate the user-mode OS interfaces in this way.

If CONFIG_BUILD_KERNEL is selected, then only a NuttX kernel will be built
with no applications.

Sub-Directories
===============

The files in the libs/libc/ directory are organized (mostly) according which file
in the include/ directory provides the prototype for library functions.  So
we have:

  audio     - This part of the audio system: nuttx/audio/audio.h
  builtin   - Support for builtin applications.  Used by nuttx/binfmt and NSH.
  dlfcn     - dlfcn.h
  endian    - endian.h
  errno     - errno.h
  hex2bin   - hex2bin.h
  libgen    - libgen.h
  locale    - locale.h
  lzf       - lzf.h
  fixedmath - fixedmath.h
  grp       - grp.h
  inttypes  - inttypes.h
  machine   - Various architecture-specific implementations.
  math      - math.h
  modlib    - Part of module and shared library logic: nuttx/lib/modlib.h
  net       - Various network-related header files: netinet/ether.h, arpa/inet.h
  pthread   - pthread.h
  pwd       - pwd.h
  queue     - queue.h
  sched     - sched.h
  semaphore - semaphore.h
  stdio     - stdio.h
  stdlib    - stdlib.h
  string    - string.h (and legacy strings.h and non-standard nuttx/b2c.h)
  time      - time.h
  uio       - sys/uio.h
  unistd    - unistd.h
  wchar     - wchar.h
  wctype    - wctype.h

Most of these are "standard" header files; some are not: hex2bin.h and
fixemath.h are non-standard.

There is also a misc/ subdirectory that contains various internal functions
and interfaces from header files that are too few to warrant their own sub-
directory:

  misc      - Nonstandard "glue" logic, debug.h, crc32.h, dirent.h

Library Database
================

Information about functions available in the NuttX C library information is
maintained in a database.  That "database" is implemented as a simple comma-
separated-value file, libc.csv.  Most spreadsheets programs will accept this
format and can be used to maintain the library database.

This library database will (eventually) be used to generate symbol library
symbol table information that can be exported to external applications.

The format of the CSV file for each line is:

  Field 1: Function name
  Field 2: The header file that contains the function prototype
  Field 3: Condition for compilation
  Field 4: The type of function return value.
  Field 5 - N+5: The type of each of the N formal parameters of the function

Each type field has a format as follows:

  type name:
        For all simpler types
  formal type | actual type:
        For array types where the form of the formal (eg. int parm[2])
        differs from the type of actual passed parameter (eg. int*).  This
        is necessary because you cannot do simple casts to array types.
  formal type | union member actual type | union member fieldname:
        A similar situation exists for unions.  For example, the formal
        parameter type union sigval -- You cannot cast a uintptr_t to
        a union sigval, but you can cast to the type of one of the union
        member types when passing the actual parameter.  Similarly, we
        cannot cast a union sigval to a uinptr_t either.  Rather, we need
        to cast a specific union member fieldname to uintptr_t.

NOTE: The tool mksymtab can be used to generate a symbol table from this CSV
file.  See nuttx/tools/README.txt for further details about the use of mksymtab.

symtab
======

Symbol Tables and Build Modes
-----------------------------
This directory provide support for a symbol table which provides all/most of
system and C library services/functions to the application and NSH.

Symbol tables have differing usefulness in different NuttX build modes:

  1. In the FLAT build (CONFIG_BUILD_FLAT), symbol tables are used to bind
     addresses in loaded ELF or NxFLAT modules to base code that usually
     resides in FLASH memory.  Both OS interfaces and user/application
     libraries are made available to the loaded module via symbol tables.

  2. Symbol tables may be of value in a protected build
     (CONFIG_BUILD_PROTECTED) where the newly started user task must
     share resources with other user code (but should use system calls to
     interact with the OS).

  3. But in the kernel build mode (CONFIG_BUILD_LOADABLE), only fully linked
     executables loadable via execl(), execv(), or posix_spawan() can used.
     There is no use for a symbol table with the kernel build since all
     memory resources are separate; nothing is share-able with the newly
     started process.

Code/Text Size Implications
---------------------------
The option can have substantial effect on system image size, mainly
code/text.  That is because the instructions to generate symtab.inc
above will cause EVERY interface in the NuttX RTOS and the C library to be
included into build.  Add to that the size of a huge symbol table.

In order to reduce the code/text size, you may want to manually prune the
auto-generated symtab.inc file to remove all interfaces that you do
not wish to include into the base FLASH image.